After last weeks zero-hour talks (and three years of unsuccessful negotiations), Spirit Airlines pilots walked off the job Saturday, wont return to the cockpit until at least Thursday, and have stranded the estimated 16,680 passengers that fly the low-cost carrier each day. The airline is refunding all canceled flights through tomorrow, trying to rebook flyers on other airlines, and offering all passengers a $100 credit toward future travels, but that could be too little, too late  as of this weekend, Spirit hadnt scheduled additional negotiations, and no pilots have crossed the picket line.